If you’ve ever strolled down White Street in Key West, specifically between Angela and Southern, you’ve probably walked right past a piece of history without even glancing up from your phone.

There’s a plot of land at 625 White Street. It looks innocent enough—lush green grass, a charming white fence, quiet vibes. You might think it’s just a nice empty lot or a park waiting to happen. But let’s be honest, in a town as old and quirky as Key West, nothing is ever just “a nice empty lot.”

That green space is actually an unmarked cemetery.

It represents a time when Key West wasn’t just dealing with the usual island chaos, but was gripped by fear, sickness, and a whole lot of confusion. We’re talking about the Civil War era, a time when the biggest enemy wasn’t a soldier with a musket, but a tiny, buzzing insect no one even suspected.

Grab a drink (maybe something with tonic, strictly for the quinine, right?), and let’s dive into the story of Yellow Fever, Dr. Mudd, and why Key West locals had to get seriously scrappy to survive.

The Twin Terrors of the Civil War

When we think of the Civil War, we usually picture battlefields and bayonets. But down here in the tropics, the war looked a little different. Key West was a Union outpost, bustling with military activity, but the soldiers stationed here quickly found out that the climate was trying to kill them faster than the Confederates ever could.

Statistics show that during the Civil War, you were actually more likely to die from disease than from a gunshot wound. In Key West, the soldiers (and the locals) were fighting off what I like to call the “Twin Terrors”: Yellow Fever and Dengue Fever.

Because of the constant ship traffic coming in from the Caribbean and our lovely, humid tropical climate, the island was basically a VIP lounge for disease transmission. And back then? They had zero clue what was actually causing it.

“Yellow Jack” vs. “Breakbone Fever”

So, what exactly were these diseases? Let’s break it down, because while they sound similar, the experience was… distinctive.

Yellow Fever (The Killer)

Locals called this “Yellow Jack.” If you caught this, you were in serious trouble. The symptoms were the stuff of nightmares: high fever and jaundice, which literally turned your skin and eyes yellow (hence the name). If you had a severe case, you were looking at internal bleeding. It was aggressive, fast, and often fatal within days.

Dengue Fever (The Torturer)

Then there was Dengue, affectionately known as “Breakbone Fever.” Sounds fun, right? While usually not fatal, it was completely debilitating. It caused such intense joint and muscle pain that it felt like your bones were actually breaking. You might survive it, but you definitely wouldn’t enjoy the process.

The Great Bonfire of Misconception

Here is where history gets a little tragic (and smoky).

We know today that mosquitoes are the culprits. Standing water plus hot weather equals a mosquito rave, and they spread these diseases like wildfire. But back in the 1860s? That science wasn’t there yet.

The popular theories were wild. People thought the sickness came from “bad air vapors” rising off rotting organic matter, or even that cemeteries themselves were leaking dangerous fumes.

Because they were terrified and didn’t know any better, the people of Key West went into panic mode. They thought the disease was sticking to objects. So, they started burning everything. If someone got sick, their family would burn their clothing, their bedding, and even their furniture.

Imagine being sick, and your family is out in the yard torching your favorite chair because they think it’s haunted by fever vapors. Families were torn apart, homes were abandoned, and people avoided their sick neighbors entirely out of sheer terror.

Check out more historic markers here

Dr. Porter and the Radical Idea of Quarantine

In the middle of this chaos, we get a local hero: Dr. Joseph Yates Porter.

If you’re standing near the Bull and Whistle (I know you know where that is), look across the street at that green house. That’s where Dr. Porter was born and died. He was a Key West native who looked at the situation and thought, maybe we should stop letting people mix and mingle.

Even though he didn’t know about the mosquitoes, he was a massive advocate for isolation.

The military and the locals started getting strict. They kept ships offshore. They sealed off the homes of the sick so people couldn’t go in or out. If a city had a bad outbreak, Key West would cut off trade with them. Military installations, including the naval station and army barracks, were repeatedly shut down to stop the spread.

It seems obvious to us now—stay home if you’re sick, right?—but back then, Dr. Porter’s insistence on quarantine was a game-changer. It slowed the outbreaks down and laid the groundwork for how we handle public health crises today.

The Fort Jefferson Connection

If you think Key West had it bad, spare a thought for the folks out at Fort Jefferson in the Dry Tortugas.

It’s a remote island fort surrounded by water, which sounds nice until you realize it lacked fresh resources and was the perfect breeding ground for mosquitoes. In the 1860s, Yellow Fever absolutely devastated the population there. We’re talking soldiers, prisoners, and laborers.

It got so bad that people were more afraid of “Yellow Jack” than they were of the imprisonment itself. To manage the spread, they actually built small hospitals on the tiny surrounding islands to isolate the sick.

Middle School History Pop Quiz

Does the name Dr. Samuel Mudd ring a bell?

He was the doctor who famously fixed up John Wilkes Booth’s leg after he assassinated President Lincoln. Because he helped Booth, Mudd was convicted and sent to prison at—you guessed it—Fort Jefferson.

During the massive 1867 outbreak, Dr. Mudd stepped up. Despite being a prisoner, he took charge and actively treated the sick, putting himself right in the line of fire for infection. His efforts saved a ton of lives, and that bravery was actually a huge reason he eventually received a pardon.

The Mystery of 625 White Street

Let’s circle back to that green field on White Street.

Originally, this was an army cemetery during the Civil War. Soldiers were buried there, with women and children buried around the edges. So, why are there no headstones today?

Well, bureaucracy happened.

There was some government cost-cutting involved—women and children rarely got markers back then anyway. Later, a decision was made to relocate the soldiers’ remains to Pensacola. But, in a tragic twist of record-keeping errors, many graves were “lost.” Some soldiers were recorded as buried twice; others just vanished from the books entirely.

So today, it sits as an unmarked resting place—a quiet reminder of a time when the island was fighting for its life.

Resilience and Remembrance

Yellow Fever changed everything for Key West. It forced the city to get serious about sanitation (goodbye, standing water!). It proved that quarantine actually works. And eventually, it pushed medical science to figure out the mosquito connection.

But more than that, it showed how resilient this island is. The people here are scrappy. They burned their furniture, they sealed their homes, and they looked out for each other in the only ways they knew how.

Next time you’re walking down White Street, take a second to pause at that white fence. It’s not just grass. It’s a monument to the people who survived the “Twin Terrors” and built the Key West we know and love today.

And hey, maybe apply a little extra bug spray while you’re at it. You know, just in case.